Researchers at Hiroshima University have discovered that engineered bacteria could aid advancements in the sustainable biofuel industry.
Acetone is a volatile solvent used for a wide range of applications, from removing nail polish to manufacturing plastics. Now, with new research conducted in Japan, it could get a sustainability boost from novel engineered bacteria developed by the team.
The group’s research on the acetone-producing bacteria, known as Moorella thermoacetica, was published in AMB Express.
Generally, acetone is generated through a cost-effective but not so sustainable method called cumene. The technique entails transforming two non-renewable resources into acetone and phenol, another chemical that facilitates the production of a number of materials, such as plastics.
According to Yutaka Nakashimada, research leader and professor in the Graduate School of Integrated Sciences for Life at Hiroshima University explained that more environmentally friendly processes – such as gas fermentation – exist, however, these can be difficult and costly to achieve.
“We thought the key is a simultaneous separation of the product from the ongoing fermentation,” Nakashimada said. “Our choice was to produce volatile chemicals by using a group of bacteria thriving at high temperatures.”
In this technique, the bacteria eat carbon dioxide and monoxide, the gaseous feedstocks of hydrogen, which can be obtained from renewable sources, to produce acetone. As they develop at a temperature greater than the boiling point of acetone, the acetone generated is a gas that evaporates and can be distilled as the bacteria make it, thus simplifying the conventional technique into a simultaneous process.
“Our development of the engineered bacteria could pave the way for developing a consolidated process with simplified and cost-effective recovery via condensation following gas fermentation on a large scale suitable for industrial production,” commented co-first author Junya Kato.
In order to cultivate this productive bacteria strain, the team genetically engineered bacteria with modified metabolism methods.
“To our knowledge, this is the first study to provide strains of bacteria that thrive at high temperatures for gas fermentation of acetone,” said Kato. “Although further study would be needed to improve the productivity for realisation of the industrial applications, the gas fermentation process can be simpler and more cost-effective than before.”
Going forward, the group intent to scale their research and analyse the productivity of their bacteria in industrial conditions.
“We may need to genetically engineer the metabolism of the strain further,” Nakashimada added. “Our ultimate goal is the industrialisation of the gas fermentation of the ‘gas-to-gas’ process that is simpler and lower-cost.”
